I've long had my eye on the Great Braxted Wall series so I thought that I'd give it a go this morning. It's a bit involved but you have to find 3 caches, each containing 2 sets of 6 numbers, put them on a grid and work out 6 sets of coords to find 6 puzzle caches.
The trouble is that you have to walk about 3.5 miles around Great Braxted estate wall to get the three caches before you get to work out any coords. At the first cache, I could see that there was a problem, you didn't know where each set of numbers went on the grid.
I decided that as I didn't have a mainframe computer with me I'd cut my losses, find some other caches locally and work out the 6 sets of coords at home.
I found 8 trad caches around Inworth and Tiptree, which was pretty good considering. So at home I set about these 6 sets of coords and realised that I must have written one of the numbers down wrong as I can't fulfil the hint. I'll have to go back and do it again.
What a git!